1. Field of the Invention
This invention is directed to improved lubricant compositions comprising monoalkylated benzothiophene-derived compounds alone as functionalized lubricant fluids or in various combinations with synthetic or mineral oil fluids, and to mineral or synthetic lubricant compositions containing said monoalkylated benezothiophene-derived compounds as multifunctional additives thereto.
2. Description of Related Art
Broadly, the novel class of hydrocarbon products of the present invention can be characterized as adducts of a hydrocarbyl substituent precursor, which can contain one or more olefin groups, and a benzothiophene compound.
Polyphenyl sulfides and polyphenyl thioethers are known and have been used as lubricants in special applications. These materials suffer from very high cost due to difficult synthesis and poor low temperature viscometrics.
Polyphenyl ethers are known for their high temperature properties as noted in D. Klamen's "Lubricants and Related Products," Verlag Chemie, 1984, pp. 116-121, and references contained therein, and in product bulletin for OS-124 polyphenyl ether by Monsanto.
Mixed polyphenyl ether-thioethers and polyphenylthioethers are noted in Monsanto bulletin for MCS-293.
Benzothiophene and dibenzothiophene are solids and, therefore, not useful as lubricating fluids in many applications; however, incorporation of linear alkyl hydrocarbon groups into dibenzothiophene eliminates these problems and provides a novel, relatively inexpensive lubricant having excellent antiwear properties. The use of these adducts as a lubricant or lubricant additive in either mineral or synthetic lubricant is unique and provides improved properties and performance benefits due to inherent synergism.
Pier et al., U.S. Pat. No. 2,258,806, is directed to the production of synthetic lubricants "under the influence of condensing catalysts" such as catalysts of the Friedel-Craft reaction.
Kusayanagi et al., U.S. Pat. No. 4,427,561, is directed to lubricant compositions comprising mineral oil, alkylbenzene and added thereto in certain specified amounts an organic sulfur compound. These compositions exhibit high wear resistance in a Flon atmosphere.
Garces, U.S. Pat. No. 4,891,448, is directed to the polyalkylation of polyaromatics in the presence of natural catalytic substances such as mordenite.
Taylor, U.S. Pat. No. 4,330,302, is directed to thermally stable liquid hydrocarbon blends comprising deoxygenated hydrocarbons containing benzothiophenes in amounts of less than about 5 ppm.
Conary et al., U.S. Pat. No. 2,652,405, is directed to a process for the production of aliphatic-substituted thianaphthenes in the presence of a sulfuric acid catalyst.
To the best of applicants' knowledge and belief the herein described alkylated benezothiophene-derived adducts have not been used previously as functional lubricant fluids or additives therefor.